A resolver is a kind of rotary position sensor that provides angular measurements by converting angular displacements to electrical signals. In general, a resolver comprises a rotor mechanically coupled to carry the angular displacement of interest to rotate in a stator. A reference winding is located at the rotor driven by a reference signal while two output windings are located at the stator being excited by the reference signal and generate two output signals, respectively, according to the reference signal and the angular displacement of interest.
Conventionally, a resolver-to-digital converter includes some resolver to analog conversion components followed by an analog to digital (A/D) converter. The two output signals are digitized using an A/D converter and peak values of the two output signals are acquired and processed to get the angular displacement. This approach requires a high speed, high precision A/D converter in order to retrieve peak values of the output signals.